On the dried-up riverbed on the border between Serbia and Romania, a dozen or so rusting hulls tower. The ships, which belonged to Nazi Germany's Black Sea Fleet, were deliberately sunk when the country retreated during World War II. Some are said to still be loaded with weapons and explosives.
According to experts, up to 200 German warships were sunk in the Danube, near the Serbian village of Prahovo.
Serbian authorities have long tried to do something about the wrecks. Some have been removed, but most remain because of the risk posed by the weapons cargo.
The low water levels in the Danube have also forced nuclear power plants along the river, which is Europe's second-longest, to shut down.
